[. . . ] DLTTM7000 Tape System Product Manual
November 10, 2003 81-60000-06
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Publication Number: 81-60000-06 A02, November 10, 2003 SERVICE CENTERS Quantum Service Center 715 Sycamore Avenue Milpitas, California 95035 Phone (888) 827-3378 FAX: (800) 4DISKFAX BBS: (800) 472-9799 Quantum Asia-Pacific Pte. 50 Tagore Lane #b1-04 Singapore, 2678 Phone: (65) 450-9333 FAX: (65) 452-2544 Quantum Customer Service Quantum Ireland, Ltd. Finnabair Industrial Park Dundalk County Louth, Ireland Phone: (353) 42-55350 Fax: (353) 45-55355
Copyright © 1996-2001 by Quantum Corporation. [. . . ] If the Link bit is 1 and the Flag bit is 0, and the task completes successfully, the drive continues the task and returns a status of INTERMEDIATE and a LINKED COMMAND COMPLETE message. If the Link bit and the Flag bit within a Control word are both set to 1, and the drive completes a command with a status of INTERMEDIATE, the drive returns a LINKED COMMAND COMPLETE message (with Flag).
5. 1. 3 Status/Error Reporting
SCSI message-level errors are communicated by messages that are defined specifically for that purpose (for example, MESSAGE PARITY ERROR, MESSAGE REJECT). SCSI command-level errors are communicated by a status code that is returned by the drive during the STATUS phase. This phase occurs at the end of each command, unless the command is terminated by one of the following events:
· · · ·
ABORT message BUS DEVICE RESET message Hard reset condition Unexpected disconnect Quantum DLT 7000 Tape System
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SCSI Commands
The status code is contained in bits 1 through 5 of the status byte. Table 54 describes the status codes returned by the drive.
NOTE In contrast to the BUSY status condition, the DRIVE NOT READY Sense Key is returned as part of the Sense data following a REQUEST SENSE command and indicates that a media access command has been issued and the medium is not ready to be accessed. For example, the medium is not installed, the medium has been unloaded, and the drive is currently initializing the medium to prepare it for access). Table 54 Status Codes
Status Code 00h 02h 08h Definition GOOD CHECK CONDITION BUSY Meaning The drive successfully completed the command. The drive cannot service the command at the moment, and its Command Descriptor Block has been discarded. This status is returned instead of a GOOD status for commands issued with the LINK bit set. Following the return of this status, the drive proceeds to the COMMAND phase for the transfer of the next linked command. Another initiator has reserved the drive when it has been reserved for another initiator with a RESERVE UNIT command (this status is never returned for INQUIRY or REQUEST SENSE commands). The drive cannot service the command at the moment, and its Command Descriptor Block has been discarded. (Returned for a tagged command when all of the drive's internal command buffers are in use, for instance. )
10h
INTERMEDIATE GOOD
18h
RESERVATION CONFLICT
28h
QUEUE FULL
Quantum DLT 7000 Tape System
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SCSI Commands
5. 1. 4 DATA-Phase Command Components
Many of the SCSI commands cause data to be transferred between the initiator and the drive. Table 55 lists the information transmitted for all of the commands. The "Length in CDB" column of Table 55 identifies the Command Descriptor Block field used by the drive to determine how much command-related data are to be transferred. The units (bytes or logical blocks) for the different Length fields are implied by the Length Field Name as follows:
Field Name Allocation Length Parameter List Length Transfer Length Byte Transfer Length Units Implied Bytes of data the drive is allowed to send to the initiator Bytes of data the initiator has available for the drive Logical number of data blocks or data bytes the initiator wants transferred or verified Bytes of data the initiator wants transferred
The DATA OUT column in Table 55 lists the information passed to the drive by the initiator as part of the command. The DATA IN column lists the information sent to the initiator by the drive. Numbers in parentheses after an item indicate the item's length in bytes. In some cases, additional length information is communicated during the DATA phase.
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Quantum DLT 7000 Tape System
SCSI Commands Table 55 DATA-Phase Command Contents
Command ERASE INQUIRY Length in CDB 0 Allocation --Standard Inquiry or a Vital Product Data page ------Log Page --Data Out (To Drive) Data In (To Initiator)
LOAD UNLOAD LOCATE LOG SELECT LOG SENSE MODE SELECT (6) / (10)
0 0 Parameter List (must be 0) Allocation Parameter List
--------Mode Parameter Header (4) Block Descriptor (8) Page(s) ---
MODE SENSE (6) / (10)
Allocation
Mode Parameter Header (4) Block Descriptor (8) Page(s) --Data Block Length Limits Buffer Offset and Allocation Length Position Identifier or SCSI Logical Address Diagnostic Page --Sense Data (18) ---
PREVENT ALLOW MEDIUM REMOVAL READ READ BLOCK LIMITS READ BUFFER READ POSITION RECEIVE DIAGNOSTIC RESULTS RELEASE UNIT REQUEST SENSE RESERVE UNIT
0 Transfer Allocation Allocation Allocation Allocation 0 Allocation 0 (Extent List Option not supported)
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SCSI Commands Table 55 DATA-Phase Command Contents (Continued)
Command REWIND SEND DIAGNOSTIC SPACE TEST UNIT READY VERIFY WRITE WRITE BUFFER WRITE FILEMARKS Length in CDB 0 Parameter List 0 0 Transfer Transfer Parameter List --Data Out Drive) --Diagnostic Page ----Data Data Microcode Image Data --(To Data In (To Initiator) -----------------
5. 1. 5
Unit Attention Condition
Queued Unit Attentions are implemented on the Quantum DLT 7000 tape drive and are maintained separately for each valid LUN for each initiator. Unit Attentions are created in each of the following circumstances:
· · · · · ·
At Power On At Bus Reset At Bus Device Reset message When the medium may have changed asynchronously When another initiator changes the Mode Parameters When a firmware (microcode) update has completed
Two queued Unit Attentions are not unusual. For example, if a unit is powered up and a tape cartridge is loaded, Power Up and Not-Ready to Ready Transition Unit Attentions are created. Due to the limited number of Unit Attention buffers, if an initiator does not clear Unit Attentions queued for it, at some point the tape drive stops generating new Unit Attentions for that initiatorlogical unit combination (existing ones will be left queued, however). [. . . ] Only when the green Operate Handle LED is steadily lit and when the audible beep sounds, lift the tape drive's cartridge Insert/Release handle. If the green Operate Handle LED is blinking, close the handle and wait for the LED to light steadily, then lift the handle and insert the cartridge. Push the cartridge fully into the tape drive.
CAUTION To prevent failures and/or damage to the handle, assist the handle to its closed position. The green Operate Handle LED extinguishes and the amber Tape in Use LED blinks to show that the tape is loading. [. . . ]